A tale of two measurements: protein-DNA interactions and gene expression in single cells.

10.33540/343 ◽  
2020 ◽  
Author(s):  
◽  
Corina Maria Markodimitraki
Blood ◽  
1998 ◽  
Vol 92 (8) ◽  
pp. 2924-2933 ◽  
Author(s):  
Tohru Ikuta ◽  
Yuet Wai Kan ◽  
Paul S. Swerdlow ◽  
Douglas V. Faller ◽  
Susan P. Perrine

Abstract The mechanisms by which pharmacologic agents stimulate γ-globin gene expression in β-globin disorders has not been fully established at the molecular level. In studies described here, nucleated erythroblasts were isolated from patients with β-globin disorders before and with butyrate therapy, and globin biosynthesis, mRNA, and protein-DNA interactions were examined. Expression of γ-globin mRNA increased twofold to sixfold above baseline with butyrate therapy in 7 of 8 patients studied. A 15% to 50% increase in γ-globin protein synthetic levels above baseline γ globin ratios and a relative decrease in β-globin biosynthesis were observed in responsive patients. Extensive new in vivo footprints were detected in erythroblasts of responsive patients in four regions of the γ-globin gene promoter, designated butyrate-response elements gamma 1-4 (BRE-G1-4). Electrophoretic mobility shift assays using BRE-G1 sequences as a probe demonstrated that new binding of two erythroid-specific proteins and one ubiquitous protein, CP2, occurred with treatment in the responsive patients and did not occur in the nonresponder. The BRE-G1 sequence conferred butyrate inducibility in reporter gene assays. These in vivo protein-DNA interactions in human erythroblasts in which γ-globin gene expression is being altered strongly suggest that nuclear protein binding, including CP2, to the BRE-G1 region of the γ-globin gene promoter mediates butyrate activity on γ-globin gene expression. © 1998 by The American Society of Hematology.


Cell Systems ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 354-366.e9
Author(s):  
Nicolas Altemose ◽  
Annie Maslan ◽  
Carolina Rios-Martinez ◽  
Andre Lai ◽  
Jonathan A. White ◽  
...  

2014 ◽  
Vol 70 (a1) ◽  
pp. C203-C203
Author(s):  
Andrzej Joachimiak ◽  
Grazyna Joachimiak ◽  
Lance Bigelow ◽  
Garrett Cobb ◽  
Youngchang Kim

Precise tuning of gene expression by transcriptional regulators determines the response to internal and external chemical signals and adjusts the metabolic machinery for many cellular processes. As a part of ongoing efforts by the Midwest Center for Structural Genomics, a number of transcription factors were selected to study protein-ligand and protein-DNA interactions. HcaR, a new member of the MarR/SlyA family of transcription regulators from soil bacteria Acinetobacter sp. ADP1, is an evolutionarily atypical regulator and represses hydroxycinnamate (hca) catabolic genes. Hydroxycinnamates containing an aromatic ring play diverse, critical roles in plant architecture and defense. HcaR regulates the expression of the hca catabolic operon, allowing this and related bacterial strains to utilize hydroxycinnamates: ferulate, p-coumarate, and caffeate as sole sources of carbon and energy. HcaR appears to be capable of responding to multiple aromatic ligands. These aromatic compounds bind to HcaR and reduce its affinity to the specific DNA sites. As a result, the transcription of genes encoding several catabolic enzymes is up-regulated. The HcaR structures of the apo-form and in a complex with several ligands: ferulic acid, 3,4 dihydroxybenzoic acid, vanillin and p-coumaric acid have been determined to understand how HcaR accommodates various aromatic compounds using the same binding pocket. We also have identified a potential DNA site for HcaR in the regulatory region upstream of the genes of the hca catabolic operon in Acinetobacter sp. ADP1 and have confirmed DNA binding by EMSA. The co-crystal structure of HcaR and palindromic 24-mer DNA has been determined for this DNA site. The crystal structures of HcaR, the apo-form, ligand-bound forms, and the specific DNA-bound form provide critical structural basis of protein-ligand (substrates or product) and protein-DNA interactions to understand the regulation of the expression of hydroxycinnamate (hca) catabolic genes. Our studies allow for better understanding of DNA-binding and regulation by this important group of transcription factors belonging to the MarR/SlyA families. This work was supported by National Institutes of Health grant GM094585 and by the U. S. Department of Energy, Office of Biological and Environmental Research, under contract DE-AC02-06CH11357.


Blood ◽  
1998 ◽  
Vol 92 (8) ◽  
pp. 2924-2933
Author(s):  
Tohru Ikuta ◽  
Yuet Wai Kan ◽  
Paul S. Swerdlow ◽  
Douglas V. Faller ◽  
Susan P. Perrine

The mechanisms by which pharmacologic agents stimulate γ-globin gene expression in β-globin disorders has not been fully established at the molecular level. In studies described here, nucleated erythroblasts were isolated from patients with β-globin disorders before and with butyrate therapy, and globin biosynthesis, mRNA, and protein-DNA interactions were examined. Expression of γ-globin mRNA increased twofold to sixfold above baseline with butyrate therapy in 7 of 8 patients studied. A 15% to 50% increase in γ-globin protein synthetic levels above baseline γ globin ratios and a relative decrease in β-globin biosynthesis were observed in responsive patients. Extensive new in vivo footprints were detected in erythroblasts of responsive patients in four regions of the γ-globin gene promoter, designated butyrate-response elements gamma 1-4 (BRE-G1-4). Electrophoretic mobility shift assays using BRE-G1 sequences as a probe demonstrated that new binding of two erythroid-specific proteins and one ubiquitous protein, CP2, occurred with treatment in the responsive patients and did not occur in the nonresponder. The BRE-G1 sequence conferred butyrate inducibility in reporter gene assays. These in vivo protein-DNA interactions in human erythroblasts in which γ-globin gene expression is being altered strongly suggest that nuclear protein binding, including CP2, to the BRE-G1 region of the γ-globin gene promoter mediates butyrate activity on γ-globin gene expression. © 1998 by The American Society of Hematology.


2019 ◽  
Author(s):  
Nicolas Altemose ◽  
Annie Maslan ◽  
Andre Lai ◽  
Jonathan A. White ◽  
Aaron M. Streets

AbstractGenome regulation depends on carefully programmed protein-DNA interactions that maintain or alter gene expression states, often by influencing chromatin organization. Most studies of these interactions to date have relied on bulk methods, which in many systems cannot capture the dynamic single-cell nature of these interactions as they modulate cell states. One method allowing for sensitive single-cell mapping of protein-DNA interactions is DNA adenine methyltransferase identification (DamID), which records a protein’s DNA-binding history by methylating adenine bases in its vicinity, then selectively amplifies and sequences these methylated regions. These interaction sites can also be visualized using fluorescent proteins that bind to methyladenines. Here we combine these imaging and sequencing technologies in an integrated microfluidic platform (μDamID) that enables single-cell isolation, imaging, and sorting, followed by DamID. We apply this system to generate paired single-cell imaging and sequencing data from a human cell line, in which we map and validate interactions between DNA and nuclear lamina proteins, providing a measure of 3D chromatin organization and broad gene regulation patterns. μDamID provides the unique ability to compare paired imaging and sequencing data for each cell and between cells, enabling the joint analysis of the nuclear localization, sequence identity, and variability of protein-DNA interactions.


2020 ◽  
Vol 15 (6) ◽  
pp. 1922-1953 ◽  
Author(s):  
Corina M. Markodimitraki ◽  
Franka J. Rang ◽  
Koos Rooijers ◽  
Sandra S. de Vries ◽  
Alex Chialastri ◽  
...  

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